Structural node of tight separable joint of bottle neck with its threaded screwed cap

ABSTRACT

The structural node of tight separable joint of bottle neck with its threaded screwed cap made of plastic includes a cylindrical neck ( 1 ) of bottle ( 2 ) and a screw cap ( 3 ) screwed onto outer thread ( 4 ) of the neck, the cap being provided with an inner thread ( 5 ) and an inner sleeve ( 8 ) joined inseparably with bottom ( 6 ) of the cap, whereas outer surface of the sleeve has at least one annular sealing tongue ( 11  or  13 ) end of which fits tight to cylindrical surface ( 12 ) of the neck ( 1 ) or end of the at least one annular tongue ( 11  or  13 ) is set tightly in eat least one circumferential groove ( 14  or  15 ) provided on inner cylindrical surface ( 12 ) of the neck ( 1 ). Moreover the cap ( 3 ), on inner surface of its sleeve portion ( 10 ), has annular offsets ( 17 ) situated above its thread ( 5 ) ends of which are tightly set in circumferential grooves ( 18 ) provided on outer surface of the neck ( 1 ) above its outer thread ( 4 ) and opposite said offset ends.

FIELD OF THE INVENTION

The subject-matter of the present invention is a structural node of tight separable joint between neck of a bottle and a threaded screwed cap, both of which are made of the same plastic, preferably of PET type.

BACKGROUND OF THE ART

Universally known bottles, especially for beverages, are typically made of elastic plastic of PET type, and caps screwed onto threaded necks of such bottles are usually made of coloured polyethylene (PE) or polyethylene of HDPE type which, to carry out the recycling process, requires the two materials to be sorted separately increasing thus significantly the cost of recycling for both of the two plastics.

Known from Polish patent description No. PL 178507 is a threaded plastic cap for closing a bottle or a container with a threaded neck, comprising a cylindrical portion with inner thread and upper bottom, said cap being screwed onto outer thread of the bottle neck, whereas between bottom of the screw cap and upper face edges of the cap there is a profiled seal covering also the axial orifice of the neck.

Moreover, lower rim of threaded portion of the cap is joined, by means of ribs, with a protection ring which, on its inner portion, is provided with locking lips catching outer protrusions provided on neck of the bottle.

Known from description of European patent No. EP 2862811 B1 is also a capping device for containers, especially bottles, with opening indicating means, comprising an inner cover connected with pouring sleeve, a cap, an outer casing, a base, and an indicator ring, whereas the plastic inner cover, fixed by means of a thread to the pouring sleeve, is provided on its inner surface with sealing means in the form of inner sing-shaped protrusion to provide sealing during the repeated capping of the bottle.

Further, from patent description No. U.S. Pat. No. 3,063,589 known is a bottle lock comprising an element composed of lower sleeve internally threaded to be joined with a container (bottle) and an upper sleeve threaded externally to be joined with its closing cap. Both sleeves are separated from each other by vertically situated ring to ensure tightness for a liquid.

An inconvenience of the above-quoted technical solutions is their excessively complex multi-component structure increasing significantly the manufacturing cost.

SUMMARY OF THE INVENTION

The objective of the present invention is to provide a simple and compact structure of structural node for tight and separable joint between threaded neck of bottle or container and a threaded screwed cap used to close the bottle or the contained which, both the container and the cap, would be made of the same material, preferably of PET type, such structure permitting to eliminate flaws and inconveniences of the above-quoted technical solutions, including elimination of necessity to segregate the materials, i.e. separate PET bottles from their caps made in the prior art of HDPE-type polyethylene and carry out recycling of the two materials separately.

The subject-matter of the structural node of tight separable joint between threaded neck of a bottle with a plastic screw cap according to the present invention consist in that the node comprises the cylindrical neck of the bottle and the cap screwed onto outer thread provided on the neck, said cap being provided with inner thread and an inner bushing joined inseparable with bottom of the screw cap, whereas outer surface of the bushing has at least one annular sealing tongue end of which fits tight to cylindrical surface of the neck or end of the at least one annular tongue is tightly fit in at least one circumferential groove provided on inner cylindrical surface of the neck. The cap, on inner surface of its sleeve-shaped portion, is preferably provided with annular offsets situated above its thread ends of which are tightly set in circumferential grooves provided on outer surface of the neck above its outer thread and opposite said offset ends, whereas the outer thread of bottle neck is provided with profiled protrusions on lower surface of its grooves, while the outer thread of the cap has profiled protrusions on upper surface of its crest, and between each two neighbouring protrusions provided on grooves of the outer thread there is a profiled protrusion provided on crest of the inner thread. The profiled protrusions provided on inner and outer thread have preferably two rectangular walls situated obliquely with respect to each other which, when seen from the front side, have the shape of isosceles triangles. It is also favourable when the inner sleeve of the cap has, on its inner surface, one stiffening annular tongue or several annular tongues or a stiffening thread, whereas length “L” of the inner sleeve equals 0.2-1.2 of length “L1” of outer cylindrical portion of the cap, while the sealing rings have thickness g=0.1-1.0 mm, and distances “b” between them are 0.1-5 mm. It is further favourable when outer diameters “D2” of annular sealing tongues are larger than the inner diameter “D1” of bottle neck so that D2=1.05-1.15 D1. It is also favourable when the cap is provided with a cylindrical element joined inseparably with its bottom, and outer surface of this cylindrical element has annular sealing tongues whereas the both cylindrical neck of the bottle and its screw cap are made of Polyethylene terephthalate (PET).

Application of the new structure of bottle neck screw cap equipped with a monolithic inner sleeve or a cylindrical element provided with stiffening elements and sealing elements and adaptation of structure of the bottle neck to said elements made possible to manufacture the cap also of plastic of PET type, also coming from recycling and analogous to this of which the bottle or the container onto which the cap is screwed is made. This eliminates the arduous necessity to segregate material of the bottle from material of its cap reducing thus the cost of recycling of the materials.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an axial cross-section view of a fragment of the upper portion of the bottle together with its neck and cap screwed onto outer thread of the neck;

FIG. 2 shows an axial cross-section view of the screw cap alone of FIG. 1;

FIG. 3 shows an axial cross-section view of an enlarged detail “R” of joint between the neck and the cap of FIG. 1;

FIG. 4 shows an axial cross-section view of a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of the neck;

FIG. 5 shows an axial cross-section view of the screw cap alone of FIG. 4;

FIG. 6 shows an axial cross-section view of the enlarged detail “S” of the joint between bottle neck and cap of FIG. 4;

FIG. 7 shows an axial cross-section view of a fragment of upper portion of the bottle together with its neck and cap screwed onto outer thread of the neck;

FIG. 8 shows an axial cross-section view of the screw cap alone of FIG. 7;

FIG. 9 shows an axial cross-section view of the enlarged detail “T” of joint between the neck and the cap of FIG. 7;

FIG. 10 shows an axial cross-section view of fragment of upper portion of bottle together with its neck and the cap screwed onto outer thread of the neck;

FIG. 11 shows an axial cross-section view of the screw cap alone of FIG. 10;

FIG. 12 shows an axial cross-section view of the enlarged detail “U” of the joint between the neck and the cap of FIG. 10;

FIG. 13 shows an axial cross-section view of a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of said neck;

FIG. 14 shows an axial cross-section view of the screw cap alone of FIG. 13;

FIG. 15 shows an axial cross-section view of the enlarged detail “V” of the joint between neck and cap of FIG. 13;

FIG. 16 shows an axial cross-section view of a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of the neck;

FIG. 17 shows an axial cross-section view of the screw cap alone of FIG. 16;

FIG. 18 shows an axial cross-section view of the enlarged detail “W” of the joint of bottle neck with the screw cap of FIG. 16;

FIG. 19 shows a perpestive view of a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of the neck with a portion of the cap being cut-out;

FIG. 20 shows a perspective view of the enlarged detail “F” of the structural node of FIG. 19;

FIG. 21 shows a perspective view of the same structural node with its component elements disassembled of FIG. 19;

FIG. 22 shows a perspective view of the screw cap of the node of FIG. 19;

FIG. 23 shows a perspective view of the same screw cap in axial cross-section along line “F-F”;

FIG. 24 shows a cross-section view of an enlarged detail “X” of thread of the cap of the node; and

FIG. 25 shows a perpestive view of an enlarged detail “Y” of outer thread of the bottle neck shown in FIG. 21.

DETAILED DESCRIPTION OF THE INVENTION

Seven example embodiments of the subject-matter of the invention are illustrated in FIGS. 1-25, showing fragments of upper portions of bottles together with their screw caps, of which FIGS. 1-3 show, in axial cross-sections, the first variant of embodiment of the structural node in which the screw cap is equipped with an inner elongated sleeve joined permanently with bottom of the cap, outer surface of said sleeve being provided with single annular sealing tongue fit tight to smooth inner surface of bottle neck, of which FIG. 1 shows a fragment of upper portion of the bottle together with its neck and cap screwed onto outer thread of the neck, in axial cross-section; FIG. 2—the screw cap alone, in axial cross-section; and FIG. 3—enlarged detail “R” of joint between the neck and the cap, in axial cross-section. FIGS. 4-6 show, in axial cross-sections, the second variant of embodiment of the same structural node, in which outer surface of the inner sleeve is provided with five annular sealing tongues situated parallel to each other and also fit tight to smooth inner surface of neck of the bottle, with lower portion of the sleeve having an inner stiffening annular offset, of which FIG. 4 shows a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of the neck, in axial cross-section; FIG. 5—the screw cap alone, in axial cross-section; and FIG. 6—enlarged detail “S” of the joint between bottle neck and cap, in axial cross-section. FIGS. 7-9 show, in axial cross-sections, the third variant of embodiment of the same structural node in which outer surface of inner sleeve is provided with one annular sealing tongue end of which is set tight in an opposite annular groove provided on smooth inner surface of bottle neck, and its lower end has an inner stiffening annular offset, of which FIG. 7 shows a fragment of upper portion of the bottle together with its neck and cap screwed onto outer thread of the neck, in axial cross-section; FIG. 8—the screw cap alone, in axial cross-section; and FIG. 9—enlarged detail “T” of joint between the neck and the cap, in axial cross-section. FIGS. 10-12 show, in axial cross-sections, the fourth variant of embodiment of the same structural node, in which outer surface of inner sleeve is provided with five annular sealing tongues situated parallel to each other ends of which are set in five annular grooves provided on inner smooth surface of neck of the bottle, of which FIG. 10 shows a fragment of upper portion of bottle together with its neck and the cap screwed onto outer thread of the neck, in axial cross-section; FIG. 11—the screw cap alone, in axial cross-section; and FIG. 12—enlarged detail “U” of the joint between the neck and the cap, in axial cross-section. FIGS. 13-15 show, in axial cross-sections, a fifth variant of embodiment of the same structural node, in which outer surface of the inner sleeve is provided with five sealing tongues situated parallel to each other ends of which are set in five annular grooves provided on inner smooth surface of the bottle neck, while lower portion of inner surface of the sleeve is provided with five stiffening annular offsets, of which FIG. 13 shows a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of said neck, in axial cross-section; FIG. 14—the screw cap alone, in axial cross-section; and FIG. 15—enlarged detail “V” of the joint between neck and cap, in axial cross-section. FIGS. 16-18 show, in axial cross-sections, a sixth variant of embodiment of the structural node, in which the cap, on inner surface of its sleeve-shaped portion and above its thread, has five annular tongues parallel to each other fit tightly in grooves provided on outer surface of bottle neck above its outer thread, of which FIG. 16 shows a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of the neck, in axial cross-section; FIG. 17—the screw cap alone, in axial cross-section; and FIG. 18 enlarged detail “W” of the joint of bottle neck with the screw cap, in axial cross-section. FIGS. 19-25 show a seventh variant of embodiment of the structural node in which the bottle neck has an outer thread in which surface of thread groove is provided with profiled sealing elements, while the cap screwed onto the neck has an inner thread crest surface of which is provided with analogous profiled sealing elements, of which FIG. 19 shows a fragment of upper portion of bottle together with its neck and cap screwed onto outer thread of the neck, in a perspective view with a portion of the cap being cut-out; FIG. 20—enlarged detail “F” of the structural node, in a perspective view; FIG. 21—the same structural node with its component elements disassembled, in a perspective view; FIG. 22—the screw cap of the node, in a perspective view; FIG. 23—the same screw cap in axial cross-section along line “F-F”; FIG. 24—enlarged detail “X” of thread of the cap of the node, in axial cross-section; and FIG. 25—enlarged detail “Y” of outer thread of the bottle neck shown in FIG. 21, in a perspective view.

Example 1

The structural node of tight joint between neck 1 of bottle 2 and its cap 3, both made of the same plastic of PET (Polyethylene terephthalate) type, according to the first variant of its embodiment shown in FIGS. 1-3, comprises a substantially cylindrical neck 1 provided with outer thread 4 and a cap 3 provided with inner thread 5; to bottom 6 of the cap fixed is, by means of weld 7, upper face of an inner sleeve 8 situated axially inside the cap, whereas the outer diameter “D” of the sleeve is smaller than the inner diameter “DI” of the neck 1 so that D=0.7 D1, and length “L” of the sleeve is larger than length “L1” of outer cylindrical portion 10 of the cap so that L=1.2 L1. Moreover, the inner sleeve 8 of the cap 3 has, in lower portion of its outer surface, an annular sealing tongue 11 with thickness g=1.0 mm and outer diameter “D2” larger than the inner diameter “D1” of the neck 1 so that D2=1.1 D1, as a result of which, after screwing the cap onto neck 1 of bottle 2, end of the annular tongue is arched on inner smooth surface 12 of the neck resulting in creation of a tight joint between the two elements.

Example 2

The structural node of tight joint of neck 1 of bottle 2 and its cap 3, also made of the same plastic of PET type according to the second variant of its embodiment shown in FIGS. 4-6, has structure identical to this of the structural node described in Example 1, and the difference between the embodiments consists only in that in the second variant of the embodiment, the inner sleeve 8 of the cap 3 has additionally, on its lower end, an inner stiffening offset 9, and moreover, the sleeve, on outer surface of its lower portion, has five identical sealing tongues 13 situated parallel with respect to each other at distances b=0.1 mm and with thickness g=0.1 mm each, as a result of which, after screwing the cap onto neck 1 of the bottle 2, all ends of the five annular tongues 13 are arched on inner smooth surface 12 of the neck resulting in increased tightness of the joint between the neck and its screw cap 3.

Example 3

The structural node of tight joint of neck 1 of bottle 2 and its cap 3, both made of the same plastic of PET type, according to the third variant of its embodiment shown in FIGS. 7-9 has structure similar to this of the structural node described in the first example of its embodiment, and the difference between the two variants consists in that in the third variant of embodiment, the lower end of inner sleeve 8 of the cap 3 has an inner stiffening offset 9, and lower end of the annular sealing offset 11 of the sleeve is set tightly in opposite circumferential groove 14 with height “h” adapted to thickness g=0.8 mm of the annular offset provided on inner smooth surface 12 of neck 1 of bottle 2 as a result of which, after screwing the cap onto the neck 1, the end of the annular offset fits tight in the groove ensuring tightness of joint between the two elements.

Example 4

The structural node of tight joint of neck 1 of bottle 2 and its cap 3, both made of a plastic of PET type, according to the fourth variant of its embodiment shown in FIGS. 10-12 has structure similar to this of the structural node described in the first example of its embodiment, and the difference between the two variants consists in that in the fourth embodiment variant, outer surface of lower portion of sleeve 8 is provided with five identical annular sealing tongues 13 situated parallel to each other at distances b=5.0 mm and with thickness g=0.3 mm each, whereas all ends of these five annular sealing offsets 13 are fit tight in five circumferential grooves 15 provided opposite said offsets on inner smooth surface 12 of the neck 1 with heights “h” adapted to thickness “g” of annular offsets 13, as a result of which, after screwing the cap onto the neck 1, ends of the annular offsets 13 set tight in said grooves result in significantly increased tightness of the joint between the two between elements of the node.

Example 5

The structural node of tight joint of neck 1 of bottle 2 and its cap 3, both made of a plastic of PET type, according to the fifth variant of its embodiment shown in FIGS. 13-15 has structure similar to this of the structural node described in the fourth example of its embodiment, and the difference between the two variants consists only in that in the fifth embodiment variant, lower portion of inner sleeve 8 of the cap 3 is provided with five inner stiffening annular offsets 16, each with thickness g1=1.0 mm and width “k”, situated parallel to each other at distances b1=0.8 mm.

Example 6

The structural node of tight joint of neck 1 of bottle 2 and its cap 3, both made of a plastic of PET type, according to the sixth variant of its embodiment shown in FIGS. 16-18 has structure similar to this of the structural node described in the first example of its embodiment, and the difference between them consists in that the length “L” of the sleeve 8 of cap 3 is smaller than length “L1” of outer cylindrical portion 10 of the cap so that L=0.2 L1 and moreover, the cap provided with inner thread 5 has also on inner surface of its cylindrical portion 10 five annular sealing tongues 17 with thickness g=0.1 mm each situated above the thread, parallel to and at distance b=0.5 mm from each other, with ends of said tongues fit tight in five annular grooves 18 provided on outer surface of neck 1, also above its outer thread 4, resulting in creation of a tight joint between the neck and the cap 3. In this node, outer diameters “D3” of annular offsets 18 of the cap 3 are smaller than the inned diameter “D4” of the neck 1 so that D4=1.1 D3.

Example 7

The structural node of tight joint of neck 1 of bottle 2 and its cap 3, also made of a plastic of PET type, according to the seventh variant of its embodiment shown in Figs. variant of its embodiment shown in FIGS. 19-25 has structure similar to this of the structural node described in the first example of its embodiment, and the difference between them consists in that length “L” of sleeve 8 of the cap 3 is smaller than length “L1” of outer cylindrical portion 10 of the cap so that L=0.5 L1 and moreover, surface of grooves of outer thread 4 of neck 1 of bottle 2 is provided with a plurality of profiled protrusions 19, while the surface of crest of the inner thread 5 of cap 3 is provided with analogous profiled protrusions 19′, whereas each of protrusions 19 and 19′ has the form of two rectangular walls 20 and 20′ situated obliquely with respect to each other and, when seen from the front side, the shape of an isosceles triangle 21 and 21′. Such form of grooves and crests of threads 4 and 5, respectively, result in that, after screwing the cap 3 onto outer thread 4 of neck 1, between each two oblique rectangular walls 20 of thread 4 of neck 1 there are two obliquely situated rectangular walls 20′ of thread 5 of the screw cap 3 ensuring thus tightness of joint between the two elements of the structural node.

Moreover, in other example embodiments of the structural node according to the invention, not shown in figures, annular stiffening offsets 16 provided in sleeve 8 of the cap 3 were replaced with an easy-to-fabricate inner thread which also functioned as a stiffening means, and the additional inner sleeve 8 fixed to bottom of the cap was replaced with a cylindrical element lower end of which had the shape of a cone, a truncated cone, or a hemisphere, which resulted in significant stiffening of the element compared to the sleeve. Moreover, in further embodiments of the node, length “L” of the inner sleeve 8 of cap 3 equalled 0.9 of length “D” of outer cylindrical portion 10 of the cap, and internal diameter “D2” of the annular sealing lips equalled 1.3 of inner diameter “DI” of neck 1 of the cap 3. 

1. A structural node of tight separable joint of a threaded neck of a bottle with a threaded screwed cap made of a plastic comprising: a neck (1) of bottle (2) and a cap (3) screwed onto an outer thread (4) of said neck, said cap being provided with an inner thread (5) and with an inner sleeve (8) joined inseparably with a bottom (6) of the cap, whereas an outer surface of the sleeve is provided with at least one annular sealing tongue end (11 or 13) of which fits tight to a cylindrical surface (12) of the neck (1) or ends of the at least one annular tongues ends (11 or 13) are set tightly in at least one circumferential grooves (14 or 15) provided on an inner side of the cylindrical surface (12) of the neck (1).
 2. The structural node according to claim 1, wherein the screwed cap (3), on inner surface of the sleeve portion (10), has annular offsets (17) situated above the inner thread (5) ends of which are tightly set in circumferential grooves (18) provided on the outer surface of the neck (1) above the outer thread (4) and opposite to said offset ends.
 3. The structural node according to claim 1, wherein the surface of grooves of the outer thread (4) of neck (1) of bottle (2) is provided with profiled protrusions (19) and the surface of crest of the inner thread (5) of the screw cap (3) is provided with similar profiled protrusions (19′), whereas between each two neighbouring protrusions (19) on grooves of the outer thread (4) there is a profiled protrusion (19′) provided on crest of the outer thread (5).
 4. The structural node according to claim 3, wherein the profiled protrusions (19 and 19′) comprise two rectangular walls (20 and 20′) situated obliquely with respect to each other and having the form of isosceles triangles (21 and 21′) when seen from the front side.
 5. The structural node according to claim 1, wherein in the inner surface of the inner sleeve (8) of the screw cap (3) is provided with one stiffening annular offset (9) or several annular offsets (16) or a stiffening thread.
 6. The structural node according to claim 1, wherein a length (L) of the inner sleeve (8) of the cap (3) equals 0.2-1.2 of a length (L1) of outer cylindrical portion (10) of the cap (3).
 7. The structural node according to claim 1, wherein the annular sealing tongues (11, 13) have thickness g=0.1-1.0 mm, and spaces (b) between them are 0.1-5 mm.
 8. The structural node according to claim 1, wherein outer diameters (D2) of the annular sealing tongues (11 and 13) are larger than an inner diameter (D1) of the neck (1) so that D2=1.05-1.15 D1.
 9. The structural node according to claim 1, wherein the cap (3) is provided with a cylindrical element joined inseparably with the bottom (6), and outer surface of the element has annular sealing tongues (11 or 13).
 10. The structural node according to claim 1, wherein the cylindrical neck (1) of bottle (2) and the cap (3) are made of Polyethylene terephthalate (PET). 